<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            width: 600px;
            height: 600px;
            border: 5px solid gray;
            display: grid;
            grid-template-rows: 200px 180px 180px;
            grid-template-columns: 200px 180px 180px;
            grid-template-areas:'a a c'
                                'd e f'
                                'g h i';
            row-gap: 20px;
            column-gap: 20px;
        }
    </style>
</head>

<body>
    <div class="box">
        <div>1</div>
        <div>2</div>
        <div>3</div>
        <div>4</div>
        <div>5</div>
        <div>6</div>
        <div>7</div>
        <div>8</div>
        <div>9</div>
    </div>
</body>

</html>